1. Field of the Invention
This invention relates to hitch adapter systems for mounting in the bed of flatbed trucks, pickup trucks and similar vehicles and securing a trailer to the vehicle for towing purposes. More particularly, the invention relates to a combined fluid and tension band-operated hitch adapter which is designed to cushion the fifth wheel, receiving pin or ball coupling device without negatively affecting the center of gravity of the trailer load. More specifically, in a first preferred embodiment the fluid and tension band-operated hitch adapter is characterized by an adapter frame having curved support beams, one end of which are hinged to the bed of a towing vehicle such as a pickup truck and the other end welded to a hitch pedestal. The hitch pedestal is designed for mounting the fifth wheel, receiving pin or ball coupling element to facilitate optimum load distribution and clearance between the trailer and tile towing vehicle.
A primary problem recognized by truckers and others towing trailers of various description is road shock, which places great stress on the towing vehicle, hitch coupling and trailer, particularly at a time when many of the roads and highways in tile United States, including interstate highways, are in poor condition.
2. Description of the Prior Art
Various devices are known in the art for mounting in the bed of a pickup truck or similar towing vehicle and securing a trailer to tile vehicle in towing configuration. U.S. Pat. No. 3,164,399, dated Jan. 5, 1965, to M. J. Lugash details a "Hinged Semi-Trailer Coupling Unit". The unit includes a fifth wheel mounted on a frame which is positioned in the bed of a pickup truck, which frame is hinged longitudinally to facilitate folding the fifth wheel and upper frame members from the horizontal to the vertical configuration and clearing the bed of the pickup truck for cargo. U.S. Pat. No. 3,826,516, dated Jul. 30, 1974, to Charles A. Weber, details a "Fifth Wheel Mounting Structure" for connecting a trailer such as a recreational vehicle to a pickup truck. The structure includes a frame mounted on the truck bed, with a fifth wheel platform on the frame for receiving a fifth wheel pin extending downwardly from the forward end of the trailer. The frame is adjustable in height and in forward and rear positions in the bed to properly distribute the trailer weight on the wheels of the two vehicles and over tile rear axle of the truck. The frame may include two downwardly-extending, vertically positioned legs having an adjustment feature for varying the elevation of the fifth wheel. A "Slide Pull and Park Bar Hitch Structure" is detailed in U.S Pat. No. 4,327,934, dated May 4, 1982, to T. F. Karnes. The structure is designed for connecting a trailer vehicle to a pickup truck by mounting a fifth wheel platform in the bed of the pickup truck. The device includes a pair of vertical frames mounted alongside the pickup truck wheel wells. The frames include a forward and rearward sliding bar which receives a horizontal member, to which is attached the fifth wheel platform, The sliding bar enables the pickup truck and trailer to travel an additional ten inches for maneuvering into a parking location at a trailer park. U.S. Pat. No. 4,429,892, dated Feb. 7, 1984, to William H. Frampton, details a "Sliding Fifth Wheel". The sliding fifth wheel is designed for attachment to a tractor for selectively moving the fifth wheel assembly of the tractor and has two drive members which are affixed to the frame of the tractor at one end and to the fifth wheel platform at the other end. The drive members may be extended or contracted from the cab of the tractor to cause the fifth wheel platform to slide. A "Fifth-Wheel Assembly" is detailed in U.S. Pat. No. 4,614,355, dated Sept. 30, 1986, to Richard L. Koch. The assembly permits the relative positions of a tractor and an associated trailer to be adjusted and includes a switching mechanism which activates an alarm in the cab of the tractor when the fifth wheel reaches a desired position. This position is a trade-off between the rear axle weight and drive axle weight. The switching mechanism includes a switch mounted on the base plate of the fifth wheel assembly and the actuated arm of the switch i s extended by means of a coil spring which i s engaged and displaced by the coupling shoe of the fifth wheel assembly. U.S. Pat. No. 4,643,443, dated Feb. 17, 1987, to Marlin V. Husa, details a "Trailer Hitch Assembly and Method". The trailer hitch assembly is removable and designed for connecting a gooseneck trailer to a pickup truck and includes a base Frame having a ball hitch mounted thereon and adapted to mount in the floor of the pickup truck box, such that the frame straddles both wheel wells and positions the ball hitch over the rear axle of the pickup truck. Two pairs of pivotable, elongated members are attached to the base frame in telescoping relationship to frictionally engage the lower surface of the upper horizontal side rail caps of the pickup truck box. Biasing between and toward each side pair of side rail engaging members is provided to secure the hitch assembly in the pickup truck bed by making a positive frictional engagement with the box side rails. Upon connection of the trailer to the hitch assembly, the weight and fore and aft pull of the trailer further secures the hitch assembly to the pickup truck box. The hitch assembly is attached to the pickup truck box without the necessity of drilling, bolting or welding.
It is an object of this invention to provide a new and improved shock-absorbing hitch adapter designed for hinged mounting in the bed of a pickup truck or similar vehicle, which hitch adapter includes a frame hinged to the vehicle bed or frame and fitted with at least two shock-absorbing devices for positioning the towing vehicle hitch mechanism at or forwardly of the center of gravity and rear axle of the towing vehicle and cushioning road shock.
Another object of this invention is to provide a fluid and tension band-operated hitch adapter fitted with a tension band or alternative rebound limiting device such as rubber, bungie cords, tension springs, or combinations of these, and at least one fluid-operated shock absorbing apparatus and hingedly mounted in the bed of a pickup truck or other "towing vehicle for positioning the fifth wheel, receiving pin or ball hitching mechanism at or forwardly of the rear axle of the vehicle and cushioning the load, without negatively affecting the center of gravity of the load being towed.
Still another object of this invention is to provide a new and improved fluid and tension band, shock-absorbing hitch adapter designed for hinged attachment to the bed of a pickup truck or other towing vehicle in pivoting, maximum travel relationship and positioning the fifth wheel, receiving pin or ball hitch coupler on a pivoting frame fitted with a tension band and one or more remotely controlled, fluid-operated shock absorbing devices to facilitate minimal road shock to the coupling mechanism, towing vehicle and the trailer being towed.
Yet another object of this invention is to provide a fluid and tension band, shock-absorbing hitch adapter which is characterized by a box-like adapter frame pivotally mounted on hinges in a towing vehicle such as a pickup truck and fitted with a compressor-filled air bag and at least one fluid-operated shock absorber, both connected to a remote controlled compressor and depressurizing system, as well as a tension band, wherein the adapter frame is cushioned for reducing road shock and resulting damage to the pickup truck or other towing vehicle and trailer and is capable of relaxed, as well as imposed travel.
A still further object of this invention is to provide a fluid and tension band-operated hitch adapter designed to removably and hingedly operate in the bed of a pickup truck or other towing vehicle with no steel-to-steel contact, the adapter frame of which is fitted with hinges on a front edge and receives a pair of rearwardly-extending, curved beams and a hitch pedestal for receiving and supporting a fifth wheel, receiving pin or ball coupling mechanism to connect a trailer to the adapter frame at a point at or forwardly of the rear axle and center of gravity of the adapter frame, and further including a tension band, a pair of shock absorbers and an air bag filled by means of a remote controlled, direct-current mechanically-operated compressor and controlled by a valve pressurizing and depressurizing system, for cushioning the adapter frame with respect to the bed or frame of the towing vehicle and reducing road shock during travel.
Another object of the invention is to provide a fluid and tension band-operated hitch adapter which utilizes high molecular weight polyethylene bushings and wear plates to eliminate steel-to-steel contact, for totally isolating the truck and trailer, the suspension travel of which hitch adapter is exaggerated by the cantilevered positioning of the coupler location.